题目内容
如图所示,细绳一端系着质量为M=0.5㎏的物体,静止在水平面上,另一端通过光滑小孔吊着质量m=0.3㎏的物体,M的中心与圆孔距离为0.2m,并知M和水平面的最大静摩擦力2N,现使此物体绕中心轴转动,角速度为下列哪些值时,能使m处于静止状态
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241404513792061.jpg)
A.3 rad/s |
B.5 rad/s |
C.6 rad/s |
D.8 rad/s |
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241404513792061.jpg)
BC
设绳子的拉力为T,转盘对M的最大静摩擦力为f
当m处于静止状态时 T=mg
当摩擦力沿半径向外达到最大时:
可得 ω1=
rad/s
当摩擦力沿半径向内达到最大时:
可得 ω2=
rad/s
平面转动时欲使m处于静止状态,角速度w的取值范围应该是:
rad/s
rad/s ,BC对;
当m处于静止状态时 T=mg
当摩擦力沿半径向外达到最大时:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140451410771.png)
可得 ω1=
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140451457352.png)
当摩擦力沿半径向内达到最大时:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140451488784.png)
可得 ω2=
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140451519411.png)
平面转动时欲使m处于静止状态,角速度w的取值范围应该是:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140451457352.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140451644416.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140451519411.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
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